US4849020A
Expired / Lapsed
US
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Asphalt compounds and method for asphalt reconditioning using microwave radiation
Assignee: POWDERTECH Inc A DE CORP
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Filing: 1987-04-20
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Granted: 1989-07-18
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Expires: 2007-04-20
Abstract
Abstract An improved asphalt composite utilizes a mixture of asphalt and a lossy microwave absorptive material normally in a granular form and dispersed homogeneously throughout the asphalt matrix. The use of a microwave material, particularly one having a Curie temperature in the range of about 100° C., enhances removal, reconditioning and reforming the asphalt during patching or repair operations which rely upon microwave radiation heating.
Inventors
- 👤 Tracy L. Osborne
- 👤 William R. Hutcheson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:24
CPC Classifications
E; E01; E01C; E01C23/00; E01C23/06; C; C08; C08K; C08K3/00; C08K3/18; C08K3/20; C08K3/22; E01C11/00; E01C11/005; E01C7/00; E01C7/08; E01C7/18; E01C7/182
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
76 words
A composite for paving comprising, in combination: a mixture of asphalt and a lossy microwave absorptive material, said lossy microwave absorptive material being dispersed in the asphalt for enhancement of heat dispersal in the mix when the mix is exposed to microwave radiation, said lossy microwave material being selected from the group consisting of spinel ferrites, hexagonal ferrites and mixtures thereof and comprising from one percent (1%) to twenty-five percent (25%) by weight of said mix.
Claim 2
Dependent Claim
76 words
A composite for paving comprising, in combination: a mixture of asphalt and a lossy microwave absorptive material, said lossy microwave absorptive material being dispersed in the asphalt for enhancement of heat dispersal in the mix when the mix is exposed to microwave radiation, said lossy microwave material being selected from the group consisting of spinel ferrites, hexagonal ferrites and mixtures thereof and comprising from one percent (1%) to twenty-five percent (25%) by weight of said mix.
Claim 3
Dependent Claim
22 words
A composite as in claim 1 wherein the lossy microwave material comprises up to about 25% by volume of the composite material.
Claim 4
Dependent Claim
22 words
A composite as in claim 1 wherein the lossy microwave material comprised up to about 25% by weight of the composite material.
Claim 5
Dependent Claim
29 words
A composite as in claim 1 wherein the lossy microwave material comprises a ferromagnetic material having a Curie temperature in the range of 50° C. to about 700° C.
Claim 6
Dependent Claim
17 words
A composite as in claim 1 wherein the lossy microwave material is homogeneously mixed in the asphalt.
Claim 7
Dependent Claim
28 words
A composite as in claim 1 wherein the mass of the lossy microwave materials is less than the mass of the asphalt per unit volume of the mixture.
Claim 8
Dependent Claim
15 words
A composite as in claim 1 wherein the lossy microwave material is a spinel ferrite.
Claim 9
Dependent Claim
89 words
An improved method for fabricating a repairable asphaltic paving material comprising the steps of: (a) measuring a volume of asphalt; (b) adding a volume of lossy microwave absorptive material selected from the group consisting of spinel ferrites, hexagonal ferrites and mixtures thereof to the asphalt to form a mix wherein; and (c) mixing the asphalt and the absorptive material to disperse the absorptive material in the matrix of the asphalt from one percent (1%) to twenty-five percent (25%) of the mix is comprised of said lossy microwave absorptive material.
Claim 10
Dependent Claim
89 words
An improved method for fabricating a repairable asphaltic paving material comprising the steps of: (a) measuring a volume of asphalt; (b) adding a volume of lossy microwave absorptive material selected from the group consisting of spinel ferrites, hexagonal ferrites and mixtures thereof to the asphalt to form a mix wherein; and (c) mixing the asphalt and the absorptive material to disperse the absorptive material in the matrix of the asphalt from one percent (1%) to twenty-five percent (25%) of the mix is comprised of said lossy microwave absorptive material.
Claim 11
Dependent Claim
83 words
A composite for paving comprising in combination: a mixture of asphalt and a lossy microwave absorptive material, said lossy microwave material being dispersed in the asphalt for enhancement of heat dispersal in the mix when the mix is exposed to microwave radiation, said lossy microwave material comprising a ferrite material at least in part selected from the group consisting of spinel ferrites, hexagonal ferrites and mixture thereof, said lossy microwave material comprising from one percent (1%) to twenty-five percent (25%) of the mixture.
Claim 12
Dependent Claim
83 words
A composite for paving comprising in combination: a mixture of asphalt and a lossy microwave absorptive material, said lossy microwave material being dispersed in the asphalt for enhancement of heat dispersal in the mix when the mix is exposed to microwave radiation, said lossy microwave material comprising a ferrite material at least in part selected from the group consisting of spinel ferrites, hexagonal ferrites and mixture thereof, said lossy microwave material comprising from one percent (1%) to twenty-five percent (25%) of the mixture.
Claim 13
Dependent Claim
14 words
The composition of claim 9 wherein said ferrite is Fe 3 O 4 .
Claim 14
Dependent Claim
14 words
The improved composition of claim 10 in combination with other lossy microwave absorptive material.
Claim 15
Dependent Claim
93 words
A composite for paving, comprising, in combination: a mixture of asphalt and from one percent (1%) to twenty-five (25%) of a lossy microwave material as an additive to the asphalt, said material being dispersed in the asphalt for enhancement of heat dispersal in the mix when the mix is exposed to microwave radiation, said lossy microwave material comprising a ferromagnetic material selected from the group consisting of spinel ferrites, hexagonal ferrites and mixtures thereof having a Curie temperature in the range of 50° to 700° C. and also having a high volume resistivity.
Claim 16
Dependent Claim
93 words
A composite for paving, comprising, in combination: a mixture of asphalt and from one percent (1%) to twenty-five (25%) of a lossy microwave material as an additive to the asphalt, said material being dispersed in the asphalt for enhancement of heat dispersal in the mix when the mix is exposed to microwave radiation, said lossy microwave material comprising a ferromagnetic material selected from the group consisting of spinel ferrites, hexagonal ferrites and mixtures thereof having a Curie temperature in the range of 50° to 700° C. and also having a high volume resistivity.
Claim 17
Dependent Claim
22 words
The improved composition of claim 12 wherein the percent by weight of lossy microwave material in the composite is less than 5%.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |